Modelling and theoretical analysis of a high temperature heat pump system with two-stage centrifugal compressor

A high temperature heat pump system utilising produced water, which is a main byproduct in oil fields, is presented, and its steady state simulation model is established. This is an alternative to water boil in the field of district heating. The model includes submodels for key components, such as two-stage centrifugal compressor with one economiser, shell and tube condenser, expansion valve, flooded evaporator and suction line heat exchanger. By combining a modular method with a dimidiate method, the simulation algorithm is developed with the objective of requiring only input parameters that are readily available to the design engineer and negating any additional constraint on system operation. The simulation results indicate that the high temperature heat pump with the coefficient of performance of 3·18 would save over 15% energy compared with traditional boil.